Tornado Watch 676

Issued

Nov 11, 2012, 12:53 PM CST (18:53 UTC)

Expired

Nov 11, 2012, 7:00 PM CST

In force

6 hr

Issued by

the Storm Prediction Center

Largest hail expected

1.5 in

Strongest gust expected

60 kt

The Shreveport radar (KSHV), 103 km from the middle of the area, began a volume at 18:54 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

Two or more tornadoes

40%

One or more EF2 to EF5 tornadoes

10%

Ten or more severe wind reports

40%

One or more gusts of 65 knots or more

10%

Ten or more severe hail reports

30%

One or more hailstones of 2 inches or more

10%

Six or more combined severe hail and wind reports

70%

• Mesoscale Discussion 2117Nov 11, 10:12 AM CST
• Mesoscale Discussion 2118Nov 11, 2:47 PM CST
• Mesoscale Discussion 2119Nov 11, 6:32 PM CST

742 
WWUS20 KWNS 111857
SEL6
SPC WW 111857
ARZ000-LAZ000-OKZ000-TXZ000-120100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 676
NWS STORM PREDICTION CENTER NORMAN OK
1255 PM CST SUN NOV 11 2012

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

       SOUTHWEST ARKANSAS
       NORTHWEST LOUISIANA
       EXTREME SOUTHEAST OKLAHOMA
       NORTHEAST TEXAS

EFFECTIVE THIS SUNDAY AFTERNOON AND EVENING FROM 1255 PM UNTIL
700 PM CST.

TORNADOES...HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 70 STATUTE
MILES EAST AND WEST OF A LINE FROM 55 MILES SOUTH OF TYLER TEXAS
TO 25 MILES NORTHWEST OF HOT SPRINGS ARKANSAS.  FOR A COMPLETE
DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE UPDATE
(WOUS64 KWNS WOU6).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

DISCUSSION...PRE-FRONTAL BAND OF STORMS OVER NERN TX INTO EXTREME
SWRN AR IS EXPECTED TO SPREAD NEWD THIS AFTERNOON...WITH NEW STORM
DEVELOPMENT CONTINUING ON THE SRN END OF THE BAND.  ADDITIONAL
STORMS MAY FORM ALONG THE ADVANCING COLD FRONT AS IT MOVES ACROSS
NRN TX AND EXTREME SERN OK/SWRN AR.  STRONG LOW LEVEL AND DEEP LAYER
SHEAR COUPLED WITH SUFFICIENT INSTABILITY...ESPECIALLY OVER NERN TX
WHERE CAPE IS NEAR 1000 J/KG...WILL PROMOTE INTENSIFICATION OF
CONVECTION THIS AFTERNOON WITH A FEW SEVERE STORMS
EXPECTED...INCLUDING A THREAT FOR SEVERAL TORNADIC SUPERCELLS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
450. MEAN STORM MOTION VECTOR 22040.


...WEISS

Tornado Watches in Texas, 2012Tornado Watches in Arkansas, 2012Tornado Watches in Louisiana, 2012Every tornado watch in 2012

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.